/* The Editor object manages the content of the editable frame. It
 * catches events, colours nodes, and indents lines. This file also
 * holds some functions for transforming arbitrary DOM structures into
 * plain sequences of <span> and <br> elements
 */

// Make sure a string does not contain two consecutive 'collapseable'
// whitespace characters.
function makeWhiteSpace(n) {
  var buffer = [], nb = true;
  for (; n > 0; n--) {
	buffer.push((nb || n == 1) ? nbsp : " ");
	nb = !nb;
  }
  return buffer.join("");
}

// Create a set of white-space characters that will not be collapsed
// by the browser, but will not break text-wrapping either.
function fixSpaces(string) {
  if (string.charAt(0) == " ") string = nbsp + string.slice(1);
  return string.replace(/[\t \u00a0]{2,}/g, function(s) {return makeWhiteSpace(s.length);});
}

function cleanText(text) {
  return text.replace(/\u00a0/g, " ").replace(/\u200b/g, "");
}

// Create a SPAN node with the expected properties for document part
// spans.
function makePartSpan(value, doc) {
  var text = value;
  if (value.nodeType == 3) text = value.nodeValue;
  else value = doc.createTextNode(text);

  var span = doc.createElement("SPAN");
  span.isPart = true;
  span.appendChild(value);
  span.currentText = text;
  return span;
}

// On webkit, when the last BR of the document does not have text
// behind it, the cursor can not be put on the line after it. This
// makes pressing enter at the end of the document occasionally do
// nothing (or at least seem to do nothing). To work around it, this
// function makes sure the document ends with a span containing a
// zero-width space character. The traverseDOM iterator filters such
// character out again, so that the parsers won't see them. This
// function is called from a few strategic places to make sure the
// zwsp is restored after the highlighting process eats it.
var webkitLastLineHack = webkit ?
  function(container) {
	var last = container.lastChild;
	if (!last || !last.isPart || last.textContent != "\u200b")
	  container.appendChild(makePartSpan("\u200b", container.ownerDocument));
  } : function() {};

var Editor = (function(){
  // The HTML elements whose content should be suffixed by a newline
  // when converting them to flat text.
  var newlineElements = {"P": true, "DIV": true, "LI": true};

  function asEditorLines(string) {
	return fixSpaces(string.replace(/\t/g, "  ").replace(/\u00a0/g, " ")).replace(/\r\n?/g, "\n").split("\n");
  }

  // Helper function for traverseDOM. Flattens an arbitrary DOM node
  // into an array of textnodes and <br> tags.
  function simplifyDOM(root) {
	var doc = root.ownerDocument;
	var result = [];
	var leaving = true;

	function simplifyNode(node) {
	  if (node.nodeType == 3) {
		var text = node.nodeValue = fixSpaces(node.nodeValue.replace(/[\r\u200b]/g, "").replace(/\n/g, " "));
		if (text.length) leaving = false;
		result.push(node);
	  }
	  else if (node.nodeName == "BR" && node.childNodes.length == 0) {
		leaving = true;
		result.push(node);
	  }
	  else {
		forEach(node.childNodes, simplifyNode);
		if (!leaving && newlineElements.hasOwnProperty(node.nodeName)) {
		  leaving = true;
		  result.push(doc.createElement("BR"));
		}
	  }
	}

	simplifyNode(root);
	return result;
  }

  // Creates a MochiKit-style iterator that goes over a series of DOM
  // nodes. The values it yields are strings, the textual content of
  // the nodes. It makes sure that all nodes up to and including the
  // one whose text is being yielded have been 'normalized' to be just
  // <span> and <br> elements.
  // See the story.html file for some short remarks about the use of
  // continuation-passing style in this iterator.
  function traverseDOM(start){
	function yield(value, c){cc = c; return value;}
	function push(fun, arg, c){return function(){return fun(arg, c);};}
	function stop(){cc = stop; throw StopIteration;};
	var cc = push(scanNode, start, stop);
	var owner = start.ownerDocument;
	var nodeQueue = [];

	// Create a function that can be used to insert nodes after the
	// one given as argument.
	function pointAt(node){
	  var parent = node.parentNode;
	  var next = node.nextSibling;
	  return function(newnode) {
		parent.insertBefore(newnode, next);
	  };
	}
	var point = null;

	// Insert a normalized node at the current point. If it is a text
	// node, wrap it in a <span>, and give that span a currentText
	// property -- this is used to cache the nodeValue, because
	// directly accessing nodeValue is horribly slow on some browsers.
	// The dirty property is used by the highlighter to determine
	// which parts of the document have to be re-highlighted.
	function insertPart(part){
	  var text = "\n";
	  if (part.nodeType == 3) {
		select.snapshotChanged();
		part = makePartSpan(part, owner);
		text = part.currentText;
	  }
	  part.dirty = true;
	  nodeQueue.push(part);
	  point(part);
	  return text;
	}

	// Extract the text and newlines from a DOM node, insert them into
	// the document, and yield the textual content. Used to replace
	// non-normalized nodes.
	function writeNode(node, c){
	  var toYield = [];
	  forEach(simplifyDOM(node), function(part) {
		toYield.push(insertPart(part));
	  });
	  return yield(toYield.join(""), c);
	}

	// Check whether a node is a normalized <span> element.
	function partNode(node){
	  if (node.isPart && node.childNodes.length == 1 && node.firstChild.nodeType == 3) {
		node.currentText = node.firstChild.nodeValue;
		return !/[\n\t\r]/.test(node.currentText);
	  }
	  return false;
	}

	// Handle a node. Add its successor to the continuation if there
	// is one, find out whether the node is normalized. If it is,
	// yield its content, otherwise, normalize it (writeNode will take
	// care of yielding).
	function scanNode(node, c){
	  if (node.nextSibling)
		c = push(scanNode, node.nextSibling, c);

	  if (partNode(node)){
		nodeQueue.push(node);
		return yield(node.currentText, c);
	  }
	  else if (node.nodeName == "BR") {
		nodeQueue.push(node);
		return yield("\n", c);
	  }
	  else {
		point = pointAt(node);
		removeElement(node);
		return writeNode(node, c);
	  }
	}

	// MochiKit iterators are objects with a next function that
	// returns the next value or throws StopIteration when there are
	// no more values.
	return {next: function(){return cc();}, nodes: nodeQueue};
  }

  // Determine the text size of a processed node.
  function nodeSize(node) {
	if (node.nodeName == "BR")
	  return 1;
	else
	  return node.currentText.length;
  }

  // Search backwards through the top-level nodes until the next BR or
  // the start of the frame.
  function startOfLine(node) {
	while (node && node.nodeName != "BR") node = node.previousSibling;
	return node;
  }
  function endOfLine(node, container) {
	if (!node) node = container.firstChild;
	else if (node.nodeName == "BR") node = node.nextSibling;

	while (node && node.nodeName != "BR") node = node.nextSibling;
	return node;
  }

  // Client interface for searching the content of the editor. Create
  // these by calling CodeMirror.getSearchCursor. To use, call
  // findNext on the resulting object -- this returns a boolean
  // indicating whether anything was found, and can be called again to
  // skip to the next find. Use the select and replace methods to
  // actually do something with the found locations.
  function SearchCursor(editor, string, fromCursor) {
	this.editor = editor;
	this.history = editor.history;
	this.history.commit();

	// Are we currently at an occurrence of the search string?
	this.atOccurrence = false;
	// The object stores a set of nodes coming after its current
	// position, so that when the current point is taken out of the
	// DOM tree, we can still try to continue.
	this.fallbackSize = 15;
	var cursor;
	// Start from the cursor when specified and a cursor can be found.
	if (fromCursor && (cursor = select.cursorPos(this.editor.container))) {
	  this.line = cursor.node;
	  this.offset = cursor.offset;
	}
	else {
	  this.line = null;
	  this.offset = 0;
	}
	this.valid = !!string;

	// Create a matcher function based on the kind of string we have.
	var target = string.split("\n"), self = this;;
	this.matches = (target.length == 1) ?
	  // For one-line strings, searching can be done simply by calling
	  // indexOf on the current line.
	  function() {
		var match = cleanText(self.history.textAfter(self.line).slice(self.offset)).indexOf(string);
		if (match > -1)
		  return {from: {node: self.line, offset: self.offset + match},
				  to: {node: self.line, offset: self.offset + match + string.length}};
	  } :
	  // Multi-line strings require internal iteration over lines, and
	  // some clunky checks to make sure the first match ends at the
	  // end of the line and the last match starts at the start.
	  function() {
		var firstLine = cleanText(self.history.textAfter(self.line).slice(self.offset));
		var match = firstLine.lastIndexOf(target[0]);
		if (match == -1 || match != firstLine.length - target[0].length)
		  return false;
		var startOffset = self.offset + match;

		var line = self.history.nodeAfter(self.line);
		for (var i = 1; i < target.length - 1; i++) {
		  if (cleanText(self.history.textAfter(line)) != target[i])
			return false;
		  line = self.history.nodeAfter(line);
		}

		if (cleanText(self.history.textAfter(line)).indexOf(target[target.length - 1]) != 0)
		  return false;

		return {from: {node: self.line, offset: startOffset},
				to: {node: line, offset: target[target.length - 1].length}};
	  };
  }

  SearchCursor.prototype = {
	findNext: function() {
	  if (!this.valid) return false;
	  this.atOccurrence = false;
	  var self = this;

	  // Go back to the start of the document if the current line is
	  // no longer in the DOM tree.
	  if (this.line && !this.line.parentNode) {
		this.line = null;
		this.offset = 0;
	  }

	  // Set the cursor's position one character after the given
	  // position.
	  function saveAfter(pos) {
		if (self.history.textAfter(pos.node).length < pos.offset) {
		  self.line = pos.node;
		  self.offset = pos.offset + 1;
		}
		else {
		  self.line = self.history.nodeAfter(pos.node);
		  self.offset = 0;
		}
	  }

	  while (true) {
		var match = this.matches();
		// Found the search string.
		if (match) {
		  this.atOccurrence = match;
		  saveAfter(match.from);
		  return true;
		}
		this.line = this.history.nodeAfter(this.line);
		this.offset = 0;
		// End of document.
		if (!this.line) {
		  this.valid = false;
		  return false;
		}
	  }
	},

	select: function() {
	  if (this.atOccurrence) {
		select.setCursorPos(this.editor.container, this.atOccurrence.from, this.atOccurrence.to);
		select.scrollToCursor(this.editor.container);
	  }
	},

	replace: function(string) {
	  if (this.atOccurrence) {
		var end = this.editor.replaceRange(this.atOccurrence.from, this.atOccurrence.to, string);
		this.line = end.node;
		this.offset = end.offset;
		this.atOccurrence = false;
	  }
	}
  };

  // The Editor object is the main inside-the-iframe interface.
  function Editor(options) {
	this.options = options;
	window.indentUnit = options.indentUnit;
	this.parent = parent;
	this.doc = document;
	var container = this.container = this.doc.body;
	this.win = window;
	this.history = new History(container, options.undoDepth, options.undoDelay,
							   this, options.onChange);
	var self = this;

	if (!Editor.Parser)
	  throw "No parser loaded.";
	if (options.parserConfig && Editor.Parser.configure)
	  Editor.Parser.configure(options.parserConfig);

	if (!options.readOnly)
	  select.setCursorPos(container, {node: null, offset: 0});

	this.dirty = [];
	if (options.content)
	  this.importCode(options.content);
	else // FF acts weird when the editable document is completely empty
	  container.appendChild(this.doc.createElement("BR"));

	if (!options.readOnly) {
	  if (options.continuousScanning !== false) {
		this.scanner = this.documentScanner(options.linesPerPass);
		this.delayScanning();
	  }

	  function setEditable() {
		// In IE, designMode frames can not run any scripts, so we use
		// contentEditable instead.
		if (document.body.contentEditable != undefined && internetExplorer)
		  document.body.contentEditable = "true";
		else
		  document.designMode = "on";

		document.documentElement.style.borderWidth = "0";
		if (!options.textWrapping)
		  container.style.whiteSpace = "nowrap";
	  }

	  // If setting the frame editable fails, try again when the user
	  // focus it (happens when the frame is not visible on
	  // initialisation, in Firefox).
	  try {
		setEditable();
	  }
	  catch(e) {
		var focusEvent = addEventHandler(document, "focus", function() {
		  focusEvent();
		  setEditable();
		}, true);
	  }

	  addEventHandler(document, "keydown", method(this, "keyDown"));
	  addEventHandler(document, "keypress", method(this, "keyPress"));
	  addEventHandler(document, "keyup", method(this, "keyUp"));

	  function cursorActivity() {self.cursorActivity(false);}
	  addEventHandler(document.body, "mouseup", cursorActivity);
	  addEventHandler(document.body, "paste", function(event) {
		cursorActivity();
		if (internetExplorer) {
		  self.replaceSelection(window.clipboardData.getData("Text"));
		  event.stop();
		}
	  });
	  addEventHandler(document.body, "cut", cursorActivity);

	  if (this.options.autoMatchParens)
		addEventHandler(document.body, "click", method(this, "scheduleParenBlink"));
	}
  }

  function isSafeKey(code) {
	return (code >= 16 && code <= 18) || // shift, control, alt
		   (code >= 33 && code <= 40); // arrows, home, end
  }

  Editor.prototype = {
	// Import a piece of code into the editor.
	importCode: function(code) {
	  this.history.push(null, null, asEditorLines(code));
	  this.history.reset();
	},

	// Extract the code from the editor.
	getCode: function() {
	  if (!this.container.firstChild)
		return "";

	  var accum = [];
	  select.markSelection(this.win);
	  forEach(traverseDOM(this.container.firstChild), method(accum, "push"));
	  webkitLastLineHack(this.container);
	  select.selectMarked();
	  return cleanText(accum.join(""));
	},

	checkLine: function(node) {
	  if (node === false || !(node == null || node.parentNode == this.container))
		throw parent.CodeMirror.InvalidLineHandle;
	},

	cursorPosition: function(start) {
	  if (start == null) start = true;
	  var pos = select.cursorPos(this.container, start);
	  if (pos) return {line: pos.node, character: pos.offset};
	  else return {line: null, character: 0};
	},

	firstLine: function() {
	  return null;
	},

	lastLine: function() {
	  if (this.container.lastChild) return startOfLine(this.container.lastChild);
	  else return null;
	},

	nextLine: function(line) {
	  this.checkLine(line);
	  var end = endOfLine(line, this.container);
	  return end || false;
	},

	prevLine: function(line) {
	  this.checkLine(line);
	  if (line == null) return false;
	  return startOfLine(line.previousSibling);
	},

	selectLines: function(startLine, startOffset, endLine, endOffset) {
	  this.checkLine(startLine);
	  var start = {node: startLine, offset: startOffset}, end = null;
	  if (endOffset !== undefined) {
		this.checkLine(endLine);
		end = {node: endLine, offset: endOffset};
	  }
	  select.setCursorPos(this.container, start, end);
	},

	lineContent: function(line) {
	  this.checkLine(line);
	  var accum = [];
	  for (line = line ? line.nextSibling : this.container.firstChild;
		   line && line.nodeName != "BR"; line = line.nextSibling)
		accum.push(nodeText(line));
	  return cleanText(accum.join(""));
	},

	setLineContent: function(line, content) {
	  this.history.commit();
	  this.replaceRange({node: line, offset: 0},
						{node: line, offset: this.history.textAfter(line).length},
						content);
	  this.addDirtyNode(line);
	  this.scheduleHighlight();
	},

	insertIntoLine: function(line, position, content) {
	  var before = null;
	  if (position == "end") {
		before = endOfLine(line, this.container);
	  }
	  else {
		for (var cur = line ? line.nextSibling : this.container.firstChild; cur; cur = cur.nextSibling) {
		  if (position == 0) {
			before = cur;
			break;
		  }
		  var text = (cur.innerText || cur.textContent || cur.nodeValue || "");
		  if (text.length > position) {
			before = cur.nextSibling;
			content = text.slice(0, position) + content + text.slice(position);
			removeElement(cur);
			break;
		  }
		  position -= text.length;
		}
	  }

	  var lines = asEditorLines(content), doc = this.container.ownerDocument;
	  for (var i = 0; i < lines.length; i++) {
		if (i > 0) this.container.insertBefore(doc.createElement("BR"), before);
		this.container.insertBefore(makePartSpan(lines[i], doc), before);
	  }
	  this.addDirtyNode(line);
	  this.scheduleHighlight();
	},

	// Retrieve the selected text.
	selectedText: function() {
	  var h = this.history;
	  h.commit();

	  var start = select.cursorPos(this.container, true),
		  end = select.cursorPos(this.container, false);
	  if (!start || !end) return "";

	  if (start.node == end.node)
		return h.textAfter(start.node).slice(start.offset, end.offset);

	  var text = [h.textAfter(start.node).slice(start.offset)];
	  for (pos = h.nodeAfter(start.node); pos != end.node; pos = h.nodeAfter(pos))
		text.push(h.textAfter(pos));
	  text.push(h.textAfter(end.node).slice(0, end.offset));
	  return cleanText(text.join("\n"));
	},

	// Replace the selection with another piece of text.
	replaceSelection: function(text) {
	  this.history.commit();
	  var start = select.cursorPos(this.container, true),
		  end = select.cursorPos(this.container, false);
	  if (!start || !end) return;

	  end = this.replaceRange(start, end, text);
	  select.setCursorPos(this.container, start, end);
	},

	replaceRange: function(from, to, text) {
	  var lines = asEditorLines(text);
	  lines[0] = this.history.textAfter(from.node).slice(0, from.offset) + lines[0];
	  var lastLine = lines[lines.length - 1];
	  lines[lines.length - 1] = lastLine + this.history.textAfter(to.node).slice(to.offset);
	  var end = this.history.nodeAfter(to.node);
	  this.history.push(from.node, end, lines);
	  return {node: this.history.nodeBefore(end),
			  offset: lastLine.length};
	},

	getSearchCursor: function(string, fromCursor) {
	  return new SearchCursor(this, string, fromCursor);
	},

	// Re-indent the whole buffer
	reindent: function() {
	  if (this.container.firstChild)
		this.indentRegion(null, this.container.lastChild);
	},

	grabKeys: function(eventHandler, filter) {
	  this.frozen = eventHandler;
	  this.keyFilter = filter;
	},
	ungrabKeys: function() {
	  this.frozen = "leave";
	  this.keyFilter = null;
	},

	// Intercept enter and tab, and assign their new functions.
	keyDown: function(event) {
	  if (this.frozen == "leave") this.frozen = null;
	  if (this.frozen && (!this.keyFilter || this.keyFilter(event.keyCode))) {
		event.stop();
		this.frozen(event);
		return;
	  }

	  var code = event.keyCode;
	  // Don't scan when the user is typing.
	  this.delayScanning();
	  // Schedule a paren-highlight event, if configured.
	  if (this.options.autoMatchParens)
		this.scheduleParenBlink();

	  if (code == 13) { // enter
		if (event.ctrlKey) {
		  this.reparseBuffer();
		}
		else {
		  select.insertNewlineAtCursor(this.win);
		  this.indentAtCursor();
		  select.scrollToCursor(this.container);
		}
		event.stop();
	  }
	  else if (code == 9 && this.options.tabMode != "default") { // tab
		this.handleTab(!event.ctrlKey && !event.shiftKey);
		event.stop();
	  }
	  else if (code == 32 && event.shiftKey && this.options.tabMode == "default") { // space
		this.handleTab(true);
		event.stop();
	  }
	  else if ((code == 219 || code == 221) && event.ctrlKey) {
		this.blinkParens(event.shiftKey);
		event.stop();
	  }
	  else if (event.metaKey && (code == 37 || code == 39)) { // Meta-left/right
		var cursor = select.selectionTopNode(this.container);
		if (cursor === false || !this.container.firstChild) return;

		if (code == 37) select.focusAfterNode(startOfLine(cursor), this.container);
		else {
		  end = endOfLine(cursor, this.container);
		  select.focusAfterNode(end ? end.previousSibling : this.container.lastChild, this.container);
		}
		event.stop();
	  }
	  else if (event.ctrlKey || event.metaKey) {
		if ((event.shiftKey && code == 90) || code == 89) { // shift-Z, Y
		  select.scrollToNode(this.history.redo());
		  event.stop();
		}
		else if (code == 90 || code == 8) { // Z, backspace
		  select.scrollToNode(this.history.undo());
		  event.stop();
		}
		else if (code == 83 && this.options.saveFunction) { // S
		  this.options.saveFunction();
		  event.stop();
		}
	  }
	},

	// Check for characters that should re-indent the current line,
	// and prevent Opera from handling enter and tab anyway.
	keyPress: function(event) {
	  var electric = /indent|default/.test(this.options.tabMode) && Editor.Parser.electricChars;
	  // Hack for Opera, and Firefox on OS X, in which stopping a
	  // keydown event does not prevent the associated keypress event
	  // from happening, so we have to cancel enter and tab again
	  // here.
	  if ((this.frozen && (!this.keyFilter || this.keyFilter(event.keyCode))) ||
		  event.code == 13 || (event.code == 9 && this.options.tabMode != "default") ||
		  (event.keyCode == 32 && event.shiftKey && this.options.tabMode == "default"))
		event.stop();
	  else if (electric && electric.indexOf(event.character) != -1)
		this.parent.setTimeout(method(this, "indentAtCursor"), 0);
	},

	// Mark the node at the cursor dirty when a non-safe key is
	// released.
	keyUp: function(event) {
	  this.cursorActivity(isSafeKey(event.keyCode));
	},

	// Indent the line following a given <br>, or null for the first
	// line. If given a <br> element, this must have been highlighted
	// so that it has an indentation method. Returns the whitespace
	// element that has been modified or created (if any).
	indentLineAfter: function(start, direction) {
	  // whiteSpace is the whitespace span at the start of the line,
	  // or null if there is no such node.
	  var whiteSpace = start ? start.nextSibling : this.container.firstChild;
	  if (whiteSpace && !hasClass(whiteSpace, "whitespace"))
		whiteSpace = null;

	  // Sometimes the start of the line can influence the correct
	  // indentation, so we retrieve it.
	  var firstText = whiteSpace ? whiteSpace.nextSibling : (start ? start.nextSibling : this.container.firstChild);
	  var nextChars = (start && firstText && firstText.currentText) ? firstText.currentText : "";

	  // Ask the lexical context for the correct indentation, and
	  // compute how much this differs from the current indentation.
	  var newIndent = 0, curIndent = whiteSpace ? whiteSpace.currentText.length : 0;
	  if (direction != null && this.options.tabMode == "shift")
		newIndent = direction ? curIndent + indentUnit : Math.max(0, curIndent - indentUnit)
	  else if (start)
		newIndent = start.indentation(nextChars, curIndent, direction);
	  else if (Editor.Parser.firstIndentation)
		newIndent = Editor.Parser.firstIndentation(nextChars, curIndent, direction);
	  var indentDiff = newIndent - curIndent;

	  // If there is too much, this is just a matter of shrinking a span.
	  if (indentDiff < 0) {
		if (newIndent == 0) {
		  if (firstText) select.snapshotMove(whiteSpace.firstChild, firstText.firstChild, 0);
		  removeElement(whiteSpace);
		  whiteSpace = null;
		}
		else {
		  select.snapshotMove(whiteSpace.firstChild, whiteSpace.firstChild, indentDiff, true);
		  whiteSpace.currentText = makeWhiteSpace(newIndent);
		  whiteSpace.firstChild.nodeValue = whiteSpace.currentText;
		}
	  }
	  // Not enough...
	  else if (indentDiff > 0) {
		// If there is whitespace, we grow it.
		if (whiteSpace) {
		  whiteSpace.currentText = makeWhiteSpace(newIndent);
		  whiteSpace.firstChild.nodeValue = whiteSpace.currentText;
		}
		// Otherwise, we have to add a new whitespace node.
		else {
		  whiteSpace = makePartSpan(makeWhiteSpace(newIndent), this.doc);
		  whiteSpace.className = "whitespace";
		  if (start) insertAfter(whiteSpace, start);
		  else this.container.insertBefore(whiteSpace, this.container.firstChild);
		}
		if (firstText) select.snapshotMove(firstText.firstChild, whiteSpace.firstChild, curIndent, false, true);
	  }
	  if (indentDiff != 0) this.addDirtyNode(start);
	  return whiteSpace;
	},

	// Re-highlight the selected part of the document.
	highlightAtCursor: function() {
	  var pos = select.selectionTopNode(this.container, true);
	  var to = select.selectionTopNode(this.container, false);
	  if (pos === false || !to) return;
	  // Skip one node ahead to make sure the cursor itself is
	  // *inside* a highlighted line.
	  if (to.nextSibling) to = to.nextSibling;

	  select.markSelection(this.win);
	  var toIsText = to.nodeType == 3;
	  if (!toIsText) to.dirty = true;

	  // Highlight lines as long as to is in the document and dirty.
	  while (to.parentNode == this.container && (toIsText || to.dirty)) {
		var result = this.highlight(pos, 1, true);
		if (result) pos = result.node;
		if (!result || result.left) break;
	  }
	  select.selectMarked();
	},

	// When tab is pressed with text selected, the whole selection is
	// re-indented, when nothing is selected, the line with the cursor
	// is re-indented.
	handleTab: function(direction) {
	  if (this.options.tabMode == "spaces") {
		select.insertTabAtCursor(this.win);
	  }
	  else if (!select.somethingSelected(this.win)) {
		this.indentAtCursor(direction);
	  }
	  else {
		var start = select.selectionTopNode(this.container, true),
			end = select.selectionTopNode(this.container, false);
		if (start === false || end === false) return;
		this.indentRegion(start, end, direction);
	  }
	},

	// Delay (or initiate) the next paren blink event.
	scheduleParenBlink: function() {
	  if (this.parenEvent) this.parent.clearTimeout(this.parenEvent);
	  var self = this;
	  this.parenEvent = this.parent.setTimeout(function(){self.blinkParens();}, 300);
	},

	isNearParsedNode: function(node) {
	  var distance = 0;
	  while (node && (!node.parserFromHere || node.dirty)) {
		distance += (node.textContent || node.innerText || "-").length;
		if (distance > 800) return false;
		node = node.previousSibling;
	  }
	  return true;
	},

	// Take the token before the cursor. If it contains a character in
	// '()[]{}', search for the matching paren/brace/bracket, and
	// highlight them in green for a moment, or red if no proper match
	// was found.
	blinkParens: function(jump) {
	  // Clear the event property.
	  if (this.parenEvent) this.parent.clearTimeout(this.parenEvent);
	  this.parenEvent = null;

	  // Extract a 'paren' from a piece of text.
	  function paren(node) {
		if (node.currentText) {
		  var match = node.currentText.match(/^[\s\u00a0]*([\(\)\[\]{}])[\s\u00a0]*$/);
		  return match && match[1];
		}
	  }
	  // Determine the direction a paren is facing.
	  function forward(ch) {
		return /[\(\[\{]/.test(ch);
	  }

	  var ch, self = this, cursor = select.selectionTopNode(this.container, true);
	  if (!cursor || !this.isNearParsedNode(cursor)) return;
	  this.highlightAtCursor();
	  cursor = select.selectionTopNode(this.container, true);
	  if (!(cursor && ((ch = paren(cursor)) || (cursor = cursor.nextSibling) && (ch = paren(cursor)))))
		return;
	  // We only look for tokens with the same className.
	  var className = cursor.className, dir = forward(ch), match = matching[ch];

	  // Since parts of the document might not have been properly
	  // highlighted, and it is hard to know in advance which part we
	  // have to scan, we just try, and when we find dirty nodes we
	  // abort, parse them, and re-try.
	  function tryFindMatch() {
		var stack = [], ch, ok = true;;
		for (var runner = cursor; runner; runner = dir ? runner.nextSibling : runner.previousSibling) {
		  if (runner.className == className && runner.nodeName == "SPAN" && (ch = paren(runner))) {
			if (forward(ch) == dir)
			  stack.push(ch);
			else if (!stack.length)
			  ok = false;
			else if (stack.pop() != matching[ch])
			  ok = false;
			if (!stack.length) break;
		  }
		  else if (runner.dirty || runner.nodeName != "SPAN" && runner.nodeName != "BR") {
			return {node: runner, status: "dirty"};
		  }
		}
		return {node: runner, status: runner && ok};
	  }
	  // Temporarily give the relevant nodes a colour.
	  function blink(node, ok) {
		node.style.fontWeight = "bold";
		node.style.color = ok ? "#8F8" : "#F88";
		self.parent.setTimeout(function() {node.style.fontWeight = ""; node.style.color = "";}, 500);
	  }

	  while (true) {
		var found = tryFindMatch();
		if (found.status == "dirty") {
		  this.highlight(found.node, 1);
		  // Needed because in some corner cases a highlight does not
		  // reach a node.
		  found.node.dirty = false;
		  continue;
		}
		else {
		  blink(cursor, found.status);
		  if (found.node) {
			blink(found.node, found.status);
			if (jump) select.focusAfterNode(found.node.previousSibling, this.container);
		  }
		  break;
		}
	  }
	},

	// Adjust the amount of whitespace at the start of the line that
	// the cursor is on so that it is indented properly.
	indentAtCursor: function(direction) {
	  if (!this.container.firstChild) return;
	  // The line has to have up-to-date lexical information, so we
	  // highlight it first.
	  this.highlightAtCursor();
	  var cursor = select.selectionTopNode(this.container, false);
	  // If we couldn't determine the place of the cursor,
	  // there's nothing to indent.
	  if (cursor === false)
		return;
	  var lineStart = startOfLine(cursor);
	  var whiteSpace = this.indentLineAfter(lineStart, direction);
	  if (cursor == lineStart && whiteSpace)
		  cursor = whiteSpace;
	  // This means the indentation has probably messed up the cursor.
	  if (cursor == whiteSpace)
		select.focusAfterNode(cursor, this.container);
	},

	// Indent all lines whose start falls inside of the current
	// selection.
	indentRegion: function(current, end, direction) {
	  select.markSelection(this.win);
	  current = startOfLine(current);
	  end = endOfLine(end, this.container);

	  do {
		this.highlight(current);
		var hl = this.highlight(current, 1);
		this.indentLineAfter(current, direction);
		current = hl ? hl.node : null;
	  } while (current != end);
	  select.selectMarked();
	},

	// Find the node that the cursor is in, mark it as dirty, and make
	// sure a highlight pass is scheduled.
	cursorActivity: function(safe) {
	  if (internetExplorer) {
		this.container.createTextRange().execCommand("unlink");
		this.selectionSnapshot = select.selectionCoords(this.win);
	  }

	  var activity = this.options.cursorActivity;
	  if (!safe || activity) {
		var cursor = select.selectionTopNode(this.container, false);
		if (cursor === false || !this.container.firstChild) return;
		cursor = cursor || this.container.firstChild;
		if (activity) activity(cursor);
		if (!safe) {
		  this.scheduleHighlight();
		  this.addDirtyNode(cursor);
		}
	  }
	},

	reparseBuffer: function() {
	  forEach(this.container.childNodes, function(node) {node.dirty = true;});
	  if (this.container.firstChild)
		this.addDirtyNode(this.container.firstChild);
	},

	// Add a node to the set of dirty nodes, if it isn't already in
	// there.
	addDirtyNode: function(node) {
	  node = node || this.container.firstChild;
	  if (!node) return;

	  for (var i = 0; i < this.dirty.length; i++)
		if (this.dirty[i] == node) return;

	  if (node.nodeType != 3)
		node.dirty = true;
	  this.dirty.push(node);
	},

	// Cause a highlight pass to happen in options.passDelay
	// milliseconds. Clear the existing timeout, if one exists. This
	// way, the passes do not happen while the user is typing, and
	// should as unobtrusive as possible.
	scheduleHighlight: function() {
	  // Timeouts are routed through the parent window, because on
	  // some browsers designMode windows do not fire timeouts.
	  var self = this;
	  this.parent.clearTimeout(this.highlightTimeout);
	  this.highlightTimeout = this.parent.setTimeout(function(){self.highlightDirty();}, this.options.passDelay);
	},

	// Fetch one dirty node, and remove it from the dirty set.
	getDirtyNode: function() {
	  while (this.dirty.length > 0) {
		var found = this.dirty.pop();
		// IE8 sometimes throws an unexplainable 'invalid argument'
		// exception for found.parentNode
		try {
		  // If the node has been coloured in the meantime, or is no
		  // longer in the document, it should not be returned.
		  while (found && found.parentNode != this.container)
			found = found.parentNode
		  if (found && (found.dirty || found.nodeType == 3))
			return found;
		} catch (e) {}
	  }
	  return null;
	},

	// Pick dirty nodes, and highlight them, until
	// options.linesPerPass lines have been highlighted. The highlight
	// method will continue to next lines as long as it finds dirty
	// nodes. It returns an object indicating the amount of lines
	// left, and information about the place where it stopped. If
	// there are dirty nodes left after this function has spent all
	// its lines, it shedules another highlight to finish the job.
	highlightDirty: function(force) {
	  // Prevent FF from raising an error when it is firing timeouts
	  // on a page that's no longer loaded.
	  if (!window.select) return;

	  var lines = force ? Infinity : this.options.linesPerPass;
	  if (!this.options.readOnly) select.markSelection(this.win);
	  var start;
	  while (lines > 0 && (start = this.getDirtyNode())){
		var result = this.highlight(start, lines);
		if (result) {
		  lines = result.left;
		  if (result.node && result.dirty)
			this.addDirtyNode(result.node);
		}
	  }
	  if (!this.options.readOnly) select.selectMarked();
	  if (start)
		this.scheduleHighlight();
	  return this.dirty.length == 0;
	},

	// Creates a function that, when called through a timeout, will
	// continuously re-parse the document.
	documentScanner: function(linesPer) {
	  var self = this, pos = null;
	  return function() {
		// If the current node is no longer in the document... oh
		// well, we start over.
		if (pos && pos.parentNode != self.container)
		  pos = null;
		select.markSelection(self.win);
		var result = self.highlight(pos, linesPer, true);
		select.selectMarked();
		var newPos = result ? (result.node && result.node.nextSibling) : null;
		pos = (pos == newPos) ? null : newPos;
		self.delayScanning();
	  };
	},

	// Starts the continuous scanning process for this document after
	// a given interval.
	delayScanning: function() {
	  if (this.scanner) {
		this.parent.clearTimeout(this.documentScan);
		this.documentScan = this.parent.setTimeout(this.scanner, this.options.continuousScanning);
	  }
	},

	// The function that does the actual highlighting/colouring (with
	// help from the parser and the DOM normalizer). Its interface is
	// rather overcomplicated, because it is used in different
	// situations: ensuring that a certain line is highlighted, or
	// highlighting up to X lines starting from a certain point. The
	// 'from' argument gives the node at which it should start. If
	// this is null, it will start at the beginning of the frame. When
	// a number of lines is given with the 'lines' argument, it will
	// colour no more than that amount. If at any time it comes across
	// a 'clean' line (no dirty nodes), it will stop, except when
	// 'cleanLines' is true.
	highlight: function(from, lines, cleanLines){
	  var container = this.container, self = this, active = this.options.activeTokens, origFrom = from;

	  if (!container.firstChild)
		return;
	  // lines given as null means 'make sure this BR node has up to date parser information'
	  if (lines == null) {
		if (!from) return;
		else from = from.previousSibling;
	  }
	  // Backtrack to the first node before from that has a partial
	  // parse stored.
	  while (from && (!from.parserFromHere || from.dirty))
		from = from.previousSibling;
	  // If we are at the end of the document, do nothing.
	  if (from && !from.nextSibling)
		return;

	  // Check whether a part (<span> node) and the corresponding token
	  // match.
	  function correctPart(token, part){
		return !part.reduced && part.currentText == token.value && part.className == token.style;
	  }
	  // Shorten the text associated with a part by chopping off
	  // characters from the front. Note that only the currentText
	  // property gets changed. For efficiency reasons, we leave the
	  // nodeValue alone -- we set the reduced flag to indicate that
	  // this part must be replaced.
	  function shortenPart(part, minus){
		part.currentText = part.currentText.substring(minus);
		part.reduced = true;
	  }
	  // Create a part corresponding to a given token.
	  function tokenPart(token){
		var part = makePartSpan(token.value, self.doc);
		part.className = token.style;
		return part;
	  }

	  // Get the token stream. If from is null, we start with a new
	  // parser from the start of the frame, otherwise a partial parse
	  // is resumed.
	  var traversal = traverseDOM(from ? from.nextSibling : container.firstChild),
		  stream = stringStream(traversal),
		  parsed = from ? from.parserFromHere(stream) : Editor.Parser.make(stream);

	  // parts is an interface to make it possible to 'delay' fetching
	  // the next DOM node until we are completely done with the one
	  // before it. This is necessary because often the next node is
	  // not yet available when we want to proceed past the current
	  // one.
	  var parts = {
		current: null,
		// Fetch current node.
		get: function(){
		  if (!this.current)
			this.current = traversal.nodes.shift();
		  return this.current;
		},
		// Advance to the next part (do not fetch it yet).
		next: function(){
		  this.current = null;
		},
		// Remove the current part from the DOM tree, and move to the
		// next.
		remove: function(){
		  container.removeChild(this.get());
		  this.current = null;
		},
		// Advance to the next part that is not empty, discarding empty
		// parts.
		getNonEmpty: function(){
		  var part = this.get();
		  // Allow empty nodes when they are alone on a line, needed
		  // for the FF cursor bug workaround (see select.js,
		  // insertNewlineAtCursor).
		  while (part && part.nodeName == "SPAN" && part.currentText == "") {
			var old = part;
			this.remove();
			part = this.get();
			// Adjust selection information, if any. See select.js for details.
			select.snapshotMove(old.firstChild, part && (part.firstChild || part), 0);
		  }
		  return part;
		}
	  };

	  var lineDirty = false, prevLineDirty = true, lineNodes = 0;

	  // This forEach loops over the tokens from the parsed stream, and
	  // at the same time uses the parts object to proceed through the
	  // corresponding DOM nodes.
	  forEach(parsed, function(token){
		var part = parts.getNonEmpty();

		if (token.value == "\n"){
		  // The idea of the two streams actually staying synchronized
		  // is such a long shot that we explicitly check.
		  if (part.nodeName != "BR")
			throw "Parser out of sync. Expected BR.";

		  if (part.dirty || !part.indentation) lineDirty = true;
		  if (lineDirty || !from || (from.oldNextSibling != from.nextSibling)) self.history.touch(from);
		  if (from) from.oldNextSibling = from.nextSibling;
		  from = part;

		  // Every <br> gets a copy of the parser state and a lexical
		  // context assigned to it. The first is used to be able to
		  // later resume parsing from this point, the second is used
		  // for indentation.
		  part.parserFromHere = parsed.copy();
		  part.indentation = token.indentation;
		  part.dirty = false;

		  // No line argument passed means 'go at least until this node'.
		  if (lines == null && part == origFrom) throw StopIteration;

		  // A clean line with more than one node means we are done.
		  // Throwing a StopIteration is the way to break out of a
		  // MochiKit forEach loop.
		  if ((lines !== undefined && --lines <= 0) || (!lineDirty && !prevLineDirty && lineNodes > 1 && !cleanLines))
			throw StopIteration;
		  prevLineDirty = lineDirty; lineDirty = false; lineNodes = 0;
		  parts.next();
		}
		else {
		  if (part.nodeName != "SPAN")
			throw "Parser out of sync. Expected SPAN.";
		  if (part.dirty)
			lineDirty = true;
		  lineNodes++;

		  // If the part matches the token, we can leave it alone.
		  if (correctPart(token, part)){
			part.dirty = false;
			parts.next();
		  }
		  // Otherwise, we have to fix it.
		  else {
			lineDirty = true;
			// Insert the correct part.
			var newPart = tokenPart(token);
			container.insertBefore(newPart, part);
			if (active) active(newPart, token, self);
			var tokensize = token.value.length;
			var offset = 0;
			// Eat up parts until the text for this token has been
			// removed, adjusting the stored selection info (see
			// select.js) in the process.
			while (tokensize > 0) {
			  part = parts.get();
			  var partsize = part.currentText.length;
			  select.snapshotReplaceNode(part.firstChild, newPart.firstChild, tokensize, offset);
			  if (partsize > tokensize){
				shortenPart(part, tokensize);
				tokensize = 0;
			  }
			  else {
				tokensize -= partsize;
				offset += partsize;
				parts.remove();
			  }
			}
		  }
		}
	  });
	  if (lineDirty || !from || (from.oldNextSibling != from.nextSibling)) self.history.touch(from);
	  webkitLastLineHack(this.container);

	  // The function returns some status information that is used by
	  // hightlightDirty to determine whether and where it has to
	  // continue.
	  return {left: lines,
			  node: parts.getNonEmpty(),
			  dirty: lineDirty};
	}
  };

  return Editor;
})();

addEventHandler(window, "load", function() {
  var CodeMirror = window.frameElement.CodeMirror;
  CodeMirror.editor = new Editor(CodeMirror.options);
  this.parent.setTimeout(method(CodeMirror, "init"), 0);
});
